The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Motorized vehicles may include a powertrain that includes a powerplant (e.g., an engine, an electric motor, and/or a combination thereof), a multispeed transmission, and a differential or final drive train. The powerplant produces drive torque that is transmitted through one of various gear ratios of the transmission to the final drive train to drive wheels of the vehicle.
Motorized vehicles may also include brakes connected to the wheels that may be selectively actuated to decelerate and thereby stop the vehicle. Typically, the brakes are operated by a driver of the vehicle by depressing a brake pedal and thereby generating a pedal force. In vehicles equipped with a hydraulic brake system, the pedal force may be converted to a pressure of brake fluid used to actuate the brakes (hereinafter “brake apply pressure”) via a master cylinder included with the hydraulic brake system.
The brake apply pressure may be used to actuate the chassis brakes and thereby generate a brake torque used to decelerate the vehicle. In a conventional brake system, the pedal force may be directly transmitted to the master cylinder for generating the brake apply pressure. Conventional power brake systems may include a brake booster that amplifies the pedal force transmitted to the master cylinder and thereby provides braking assistance.
Alternatively, in a brake-by-wire system, the pedal force may be indirectly transmitted to the chassis brakes via the hydraulic brake system by an actuator connected to the master cylinder. The actuator may be regulated by one or more control modules to produce a desired brake torque based on a driver intended braking force. The brake-by-wire system may include a sensor that measures a displacement of the brake pedal. The brake-by-wire system may also include a sensor that measures the pedal force. One or more of the foregoing sensors may be used by the brake-by-wire system to determine the driver intended braking force. Based on the driver intended braking force, the brake-by-wire system may regulate the actuator to generate the brake apply pressure corresponding to the desired brake torque.
The brake apply pressure may be modified for a variety of reasons. For example, anti-lock braking systems may modify brake apply pressure to inhibit wheel slip that may occur on slippery or uneven roads. Similarly, vehicle stability control systems may modify brake apply pressure by apportioning the brake apply pressure among the wheels to inhibit a loss of vehicle control.